A ski binding of the abovementioned type is for example described in German OS No. 2,221,105. In this known device the locking members act against a release to the side either only in front or only in the rear, a release upwardly, however, both in front and also in the rear. A release of the boot occurs, however, only after the sole plate has separated completely from the ski and the ski boot and sole plate are released together by the ski. This mode of operation has the disadvantage that the sole plate has to travel through a relatively large zone until it is released by the locking members and separated from the ski. The times delays which occur in this large zone can possibly have negative effects on safety in particular at very high travelling speeds because a delay of the release mechanism can occur. Therefore, in the known ski binding, the initial stress of the springs which cause the release is adjusted carefully to these circumstances. The increased spring adjustment or increased initial stress of the springs would still lie in the elastic zone of the binding.
An improved heel holder for a ski binding of the abovementioned type is described in U.S. Pat. No. 4,033,603. In this construction, the locking member is mounted on the sole plate and the holding member is mounted on the ski and the heel holder can be moved with respect to the sole plate. The heel holder is held in the downhill position by a control member associated with the locking member, which control member after a pivotal movement of the rear end of the sole plate a certain number of degrees release the heel holder to effect a release of the ski boot and subsequently, under the action of the spring loading, the locking member swings the sole plate back about the pivot bearing into its initial position and holds it on the ski.
The just now described construction has the disadvantage that the heel holder always opens up upwardly, regardless of whether the outside forces which act onto the sole plate cause a release upwardly, to the side or diagonally. This has the disadvantage that the forces which are not aligned in the direction of the direct release suffer a loss in form of additional friction and only the associated vector of the parallelogram of forces is important therein. Another disadvantage of the known construction is that a later and separate adjustment of the actual heel holder to the boot is not possible, because the heel holder and the locking member are fixedly related to one another.
The purpose of the invention is now to overcome the mentioned disadvantages and to construct a heel holder of the abovementioned safety ski binding type in such a manner that, between the heel holder and the inserted ski boot, a separate and possibly adjustable thrust adjustment is provided.
The set purpose is inventively attained by the locking member engaging a locking element of the holder through a flange and the heel holder is supported on an axis which extends transversely to the longitudinal direction of the ski, which axis in turn is held gimballike on the locking member.
With the inventive construction, all goals are clearly reached. The forces which act onto the heel holder are transferred by the locking member directly onto the heel holder, because same also carries out all movements of the sole plate. If the heel holder is opened during a fall, then the boot is released without regard to how the front holding part is designed. A simple suspension device is therefore also sufficient which holds the boot in the position of use.
A particularly preferable embodiment of the invention includes a flange engaging the heel holder through a screw connection which can be adjusted in the longitudinal direction of the ski. The elasticity of the ski binding can be regulated in this manner. By adjusting the screw, the amount of overlap of the locking element and holder part is determined, so that a smaller or a larger movement of the locking member results in the release.
According to a further thought of the invention, a spring is arranged between the locking element and the flange, which spring is substantially weaker compared with the spring which causes the release and serves only for holding the locking element in the respective position. This construction permits, during an arbitrary release, an overcoming of only this weaker spring force without requiring the main spring to be operated.